Boring-machine.



PATENTBD SEPT. s 1908. 897944 F. J. WATERS.

BORING MACHINE.

APPLICATION FILED AUG. 17, 1907.

3 SHEETS-SHEET 1.

l\ x I MTQEEE E5. Mf/K PATENTED *SEPT. Q8, 1908.

3 SHEETS-SHEET 2.

F J WATERS BORING MACHINE- APPLICATION FILED .A UG.17, 1907.

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PATENTED SEPT. s, 1908.

P; J. WATERS. BORING MACHINE.

APPLICATION FILED AUG-.17, 1907.

a w m3 MTNEEEEE FRANK J. WATERS, OF PROVIDENCE, RHODE ISLAND, ASSIGNORTO WATERS ENGINE COMPANY, OF SAOO, MAINE, A CORPORATION OF MAINE.

B OBING-MACHINE Specification of Letters Patent.

Patented Sept. 8, 1908.

Application filed August 17, 1907. Serial No. 389,058.

T 0 all whom it may concern:

Be it known that I, FRANK J. WATERs, a citizen of the United States,residing at Providence, in the county of Providence and State of RhodeIsland, have invented certain new and useful Improvements inBoring-Machines, of which the following is a specification, referencebeing had therein to the accompanying drawings.

Like reference numerals indicate like parts.

' Figure 1 is a view in front elevation of my improved boring machine.Fig. 2 is a View in front elevation of the boring shaft, in which thepattern bar and the cutter bar are mounted. tion and partly in verticalsection on line a a of Fig. 4, showing the tail-stock, the boring shaft,mounted near one end within the pattern holder, together with the meansof adjusting said holder upon the machine frame. Fig. 4 is a view invertical section as seen on line o o of Fig. 3. Fig. 5 is a top planview of the pattern, pattern holder and saddle, the latter being mountedon the boring shaft. Fig. 6 is a view in top plan of the boring shaft.Fig. 7 is an inside face view of one of the halves of the boring shaft.Fig. 8 is a view in front elevation of the rocking arm or lever,together with the pattern bar and the cutter bar at its respective ends.Fig. 9 is a sectional view (on an enlarged scale) of the boring shaft,as seen' on line w w of Figs. 1 and 2. Fig. 10 is a central, verticalsection of the pattern bar (on an enlarged scale), as seen on line a xof Fig. 8. Fig. 11 is a sectional view of one end of the pattern bar, asseen on line y 3 of Fig. 10.. Fig. 12 is a perspective view of one ofthe shields to protect the cutter bar. Fig. 13 is a view, partly in endelevation on line 2 z of Fig. 1, showing the engine cylinder in positionupon the lathe carriage and the boring shaft and cutter bar within saidcylinder, during the boring operation.

My invention relates to boring machines and is intended for the boringof holes of irregular or varying cross sections, but of uniformeccentric diameters.

It consists of the novel construction, combination and arrangement ofthe several parts as hereinafter described and claimed.

In the drawings my improved machine is represented as cutting theirregularly curved bore of the cylinder of a rotary steam engine, suchas is particularly specified in my pend- Fig. 3 is a view, partly ineleva-- ing application for Letters Patent, filed herewith, being SerialNo. 389,057.

In Fig. 1 is shown a lathe of usual construction, having a centrallongitudinallyslotted bed or frame 1, ahead-stock 2, a tail stock 3,carriage 4, face plate 5 and feed screw 6, all made and operating in thecommon and well-known manner. The shaft 7 is mounted in the head-stock 2and is rotated by a pulley (not shown) and turns the face plate 5, asusual. The boring shaft 8 is mounted axially upon the center or spindle9 of the head-stock 2 and upon the center or spindle 10 of thetail-stock 3. A collar 11 supports the end of the boring shaft 8 adjacent to the head-stock 2. The face plate 5 has the usual radial slot,through which the dog 12 extends, being clamped thereto by the nuts 13,14, which engage the threaded portion thereof. The opposite end of thedog 12 is transversely bored or tapped for the reception of a set screw15, which passes also through the collar on one side thereof and bearsagainst the boring shaft 8, as seen in Figs. 1 and 2.

The carriage 4 has clamps 16 screwed thereto and supports and holds inplace the cylinder 17, through which the irregularly curved bore 18 isto be formed by the cutting tools in the cutter bar 19. This carriage 4travels on ways 20 upon the upper surface of the bed of the lathe, andthe movable tail stock 4 travels on other ways 21, parallel to the ways20, as usual. The carriage 4 moves automatically along the feed screw 6,which is rotated by gearing (not shown) and is thrown into or out ofengagement with the feed screw 6 by the handle 22, in the usual manner.The handle 23 moves the carriage 4 along the feed rack 24, but thesecarriage movements, not being any part of this invention need not befurther described, as they are well-known.

The boring shaft 8 is separately shown in Fig. 2, and on an enlargedscale in Figs. 6 and 7, and on a still larger scale in Fig. 9. It ismade in two halves abutting along the diametrical plane, indicated bythe longitudinal line 81 in Fig. 6, each half being semi-circular incross section, as seen in Fig. 9, with the inner face substantiallyplane, as shown in Figs. 7 and 9. The boring shaft 8 is concentricallyreduced at one end (adjacent to the tail-stock 3 of the lathe), asrepresented at 25. One half or longitudinal section of the boring shaft8 is cut away at intervals on its periphery, as illustrated at 26 inFig. 9, for the reception of the bolts 27, by which the two halves orsections thereof are fastened together, the other half or section beingtapped for the threaded end of each bolt 27 as seen at 28. By cuttingthe sockets or re cesses 26 of sufficient depth, the heads of the bolts27, when in holding position, he wholly within the peripheral line ofthe boring shaft 8. The boring shaft 8 has the diainetrical slot 29 (onehalf of said slot being in each half secction of the shaft), throughwhich the cutter bar 19 is mounted slidably and also has a diametricalslot 30 (one half thereof being in each half section), through which apattern bar 31 is slidably mounted.

Each half section of the boring shaft 8 has the peculiarly-shapedlongitudinal recess or 26 slot 32, shown in plan in Fig. 7 and in crosssection in Fig 9, the longitudinal sides of this recess or slot 32 areangularly inclined in the manner and for the purpose presentlyexplained. Each flange 33 of the recess or slot 32is tapped, asrepresented at 34, for the reception of bolts 27, which with the otherbolts 27, previously described, serve to fasten the two half-sections ofthe boring shaft 8 together. I

Each half-section of the boring shaft 8 has a central, radially-directedcircular aperture 35, in which is mounted, adjacent to each hub, abronze bearing 29, whose peculiar.

form in cross section is illustrated on an en- 35 larged scale, in Fig.9. Each bearing 29 has a conical seat at its inner end and a circularsocket at its outer end and also a circular concentric bore. A key 30secures each bearing 29 in position in the boring shaft 8.

A lever or oscillating arm 82 has a centrally located hub 83 on eachside, extending at a right angle. A trunnion 84 extends axially fromeach of the hubs 83 and fits rotatably in the conical seat of thebearing 29.

- This bearing 29 may be channeled for the passage of oil to lubricatethe trunnion 84. The oscillating arm 82 and each hub 83 and trunnion 84thereof are bored, as shown in Fig. 9, and a tubular pivot 85, havingone end closed, and there provided with a head 86 extends diametricallythrough the boring shaft 8, the oscillating arm 82 and the hubs andtrunnions thereof. The opposite end of the tubular pivot 85 is open andscrewthreaded both on its outer and inner surfaces. A nut 87 engageswith the exterior screw threads of the tubular pivot 85 and is containedwithin the adjacent circular socket of the bearing 29. A screw plug 89engages with the interior screw threads of the tubular pivot to closethe same at that end. The screw plug 89 is not headed and its exposedend is made to conform in surface to the peripheral curvature of theboring shaft 8, as illustrated in Fig. 9. The screw plug 89 has alongitudinal oil duct through it, indicated by dotted lines. The tubularpivot 85 has two openings 88 through it on one side. Oil introduced atthe outer end of the oil duct of the screw plug 89 passes therefrom intothe tubular pivot 85 and thence, through the two openings 88 into thespace between the bearing 29 on each side, and so lubricates eachtrunnion 84 of the oscillating arm 82. The cutter bar 19 is pivotallyconnected at 91 with the oscillating arm 82. A cutting tool 36 ismounted at each end of the cutter bar 19 in a longitudinal slot 37thereof, shown in dotted lines in Fig. 8, and is held therein inadjusted position by the set screw 38.

The right-hand end 25 of the boring shaft 8 is held by the center orspindle 10 of the tail-stock 3. The boring shaft 8 is also sup portedloosely by the pattern holder 39, which has a collar 40, whose bore isbeveled, as shown in Fig. 3. A bushing 41, made in two semi-circularsections, has its external surface tapered, but its inner surfacecylindrical, to surround the boring shaft 8. This bushing 41 extendsthrough the collar 40 and serves both to center the boring shaft 8 inposition and to take up the wear. Each half section of this splitbushing has an integral car 42, which is tapped for the passage of ascrew 43, the latter entering the pattern holder 39. Two nuts 44 and 45,the latter being a check nut, hold each half-section of the bushing 41in position.

The pattern 46 has a flange 47, shown in Fig. 4 as octagonal in form, bywhich it is secured to the flange 48 of the pattern holder 39. A saddle49 has a collar 50, through which the reduced end 25 of the boring shaft8 passes rotatably. The saddle 49 has two bent sides 51, which terminatein flanges 52, respectively. Bolts 53 fasten the flanges 52 of thesaddle to the flanges 48 of the pattern holder 39. Bolts 54 fasten theflanges 47 of the pattern 46 to the flanges 48 of the pattern holder 39.A collar 56 is mounted on the reduced end 25 of the boring shaft 8 insnug contact with the saddle collar 50, and is held in adjusted positionby the set screw 56.

The pattern 46 has a bore 57 through it, represented by the irregularcurved line in Fig. 4. This pattern bore 57 has the same diameters andcurvatures as the bore 18 which is to be cut in the engine cylinder 17.

The pattern bar 31 is shown in Figs. 2, 4 and 8, but most plainly and onan enlarged scale in Fig. 10. It is made in two longitudinal sections,fastened together by screws.

or rivets 90.

The pattern bar .31 has a slot 59 at each end in which a block 60 isslidably mounted. The block 60 has a central socket or recess 61 at itsupper end and also a screw-threaded bore, as seen in Figs. 10 and 11.The lower edge of the block 60 is formed into a concave seat, seen inFig. 10, and also has a slot 62.

A shoe 63, having in cross section a peripheral surface approximately180 in extent, is mounted loosely in said concave seat. The longitudinalsides of the slot 62 extend in directions radial to the center or axisof curvature of the oscillating bearing or shoe 63, as shown in Fig. 10.A screw 64 has a threaded shank, by which it engages the block 60, andalso a head 65, whose upper surface is in contact with the upper surfaceof the slot 59. The shoe 63 has a radially-extending stud 58, whichprojects up into the recess 62 of the block 60 to limit the oscillationof the shoe 63. The outer surface of the shoe 63 has a curvatureapproximating the curvature of the pattern, which latter is indicated bythe line 66 in Fig. 10.

At each end of the pattern bar 31 on the opposite sides thereof are theears or plates 67, L-shaped in cross section, and secured to therespective l'lalf-sections of the pattern bar 31. by the screws 68.These cars 67 are rounded at the bottom, as shown in Fig. 10, and extendbeyond the shoe 63, whose ends abut them on both sides, as seen in Fig.11.

At the center of each pattern bar 31, a bronze bearing block 35 isinserted. in a rectangular slot of said bar. It has a circular aperture,which serves as a bearing for the pivot 91 of the adjacent end of thelover or oscillating arm 82. The bearing block 35 is a little narrowerthan the rectangular slot made for its reception, and there is thusformed a clearance to allow a slight lateral play or movement of theblock 35 in said slot, to facilitate the pivotal action of the patternbar 31 upon the oscillating arm 82 in the slot 30 of the boring shaft 8.

In Fig. 12 is shown one of the shields 69 used on the opposite sides ofthe cutter bar 19. Each shield 69 is made of thin sheet metal and hasfour bent ears 70 at its corners and also an oblong central slot 71.These shields are placed as shown in Figs. 2, 3, and 8. As seen in Fig.8, the oblong slot 71 is of a size and has such location as to furnish aclearance for the pivot 91. The purpose of these shields 69 is toprotect the pivot hole for the pivot 91 from becoming clogged with thechips of the boring operation.

The pattern holder 39 is made in two halfsections and is provided withflanges, which are held together by bolts, as seen in Fig. 3. There isan octagonal inner edge or rim for the pattern holder 39, indicated bythe dotted line in Fig. 4, and in whatever position the pattern bar 31may be, its ends or ears 67 are always within said inner edge of theaperture of the pattern holder, as illustrated in Fig. 4.

The pattern holder 39 has a standard or tail piece 72, which by itsflange 73 is fastened by bolts 74 to the bottom flange 75 of the patternholder. The standard or tail piece 72 extends down through the centralaperture of the lathe, as seen in Figs. 1 and 4. The

standard 72, has a vertical slot 76, enlarged at 77. A cross bar 78rests slidingly on the ways 20, 21, of the bed of the lathe, as bestseen in Fig. 4, and through its center, which is somewhat enlarged, ahole is tapped for the reception of a bolt 80. The head 81 of the boltextends into the enlarged slot 77, as seen in Fig. 3 and shown in dottedlines in Fig. 4. Two sliding dogs 79, each having a rectangular apertureloosely surround the cross bar 78. When the pattern holder 39 isproperly adjusted lengthwise of the cross bar 78, as in Fig. 4, thesedogs 79 are slid on the cross bar 78 until they come into abutment withthe sides of the central aperture of the bed of the lathe and then theset screws 92 are tightened up and hold the pattern holder 39 in saidadjusted position. A nut 94 on the outer end of the bolt 80 secures thebolt 80, tail piece 72 and cross bar 78 together.

Having thus described the several parts of my invention, I will nowexplain its operation.

The result to be accomplished by the operation of the machine is theshaping of the bore 18 of acylinder 17 to exactly correspond to theshape of the bore 57 of the pattern 46. It is seen that in the caseshown in the drawing (Fig. 4) the line, which indicates the outline ofthe pattern bore is made up of arcs of different lengths and ofdifferent radii, thus producing an irregularly curved bore. The boreshown in Fig. 4 is intended to be the same as that represented in thecylinder shown in my said pending application for Letters Patent, towhich reference is hereby had, but it may here be defined as a cylinder,whose walls are equally distant from each other on everv line passingthrough a given point which is exterior to the geometrical center of thecylinder bore. It is desired to make the bore of the cylinder 17 ofexactly the same diametrical size and curvatures as the bore of the pattern 46. This work is done on a lathe, as shown in Fig. 1.' he cylinder1.7, is mounted and secured in position upon the carriage 4, whichserves as a work-holder, supporting the cylinder, which is to be bored,and, by means of the feed screw 6, advancing said cylinder to thecutting means for the progressive boring operation.

As shown in Fig. 3, the pattern bar 31 is thicker from front to backthan the width of the pattern 46, and the outer ends or ears 67 of thepattern bar 31 extend beyond the pattern 46, both in front and in therear, and upon both ends.

As seen in Fig. 10, the outer surface of each shoe 63 is in constantcontact with the curved surface 66 of the bore 57 of the pattern 46,such contact being established and maintained by the screw 64, whosehead 65 abuts the inner end of the slot 59 of the pattern bar 31. Eachend of the pattern bar 31 has such a shoe 63. The oscillation of theshoes 63 is due to the fact that the outer peripheral surface thereoffollows the curvatures of the pattern 46. Thus, when the radius of thecurvature of the pattern bore is less at any given point therein thanthat of another given point which the shoe 63 has ust passed, thepattern bar 31 is slid in the slot of the boring shaft 8, and so atevery diameter of the pattern bore the bar 31 is pushed in onelongitudinal direction or the other by the varying curvatures of thebore, the bar 31 being, of course, always of the same length, butsliding in the slot 30 of the boring shaft 8, as it is compelled to doby the varying diameters of the pattern bore. Such movements of thepattern bar 3]. cause the oscillating arm 82, which is pivotallyconnected thereto at 91 to rock upon its tubular pivot 85 to an equaldegree. The rocking of the oscillating arm 82, causes the cutter bar 19to move in the slot 29 to the same degree. As the oscillating arm 82 ispivotally mounted at 29", exactly in the center thereof, the slidingmovements of the cutter bar 19 are exactly the same in length as thoseof the pattern bars 31, but are in directions opposite to the movementsof the pattern bar 31.

As the pattern 46 is fixed in position, being adjustably set by theproper movement of the pattern holder 39, but the boring shaft 8 rotatesby means of the lathe pulleys the shoes 63 of the pattern bar 31accurately follow the pattern line in each rotation of the boring shaft8. Consequently, the cutters 36 give a corresponding and equal shape tothe bore 18 of the cylinder 17. The inclination of the sides 33 of therecess or slot 32 of the boring shaft 8, shown in Fig. 7, is such. as tocorrespond to the angular directions of the oscillating arm 82 in itsextremes of travel, as illustrated in Fig. 2.

The washer or nut 87 draws the head 86 of the tubular pivot 85 and thusseats the trunnions 84 of the oscillating arm 82 in the hearing 29within the boring shaft 8.

This machine is adapted to bore any rounding hole of irregular shape,which has equal diameters intersecting each other eccentrically. Theoscillation of the shoes 63 enable it to follow the contour of thepattern bore, but the stud 58 serves, by its abutting the radiallydirected sides of the recess 62, as a stop device to prevent excessiveoscillation.

It is obvious that if the boring shaft 8 were held stationary and thepattern 46 were revolved the result would be the same, and as this wouldbe a mere reversal of the arrangement hereinbefore described and embodythe same mechanical principle, such aconstruction would be within thescope of my invention. It is also obvious that instead of using a lathe,as described, an ordinary horizontal boring mill may be used, in whichcase the boring bar would feed instead of the work,

and the tail piece 72 would travel in the slot of the boring mill.

I claim as a novel and useful invention and desire to secure by LettersPatent 1. In a boring machine, the combination of a rotatable boringshaft having two diametrical slots and a central longitudinal recess orslot extending between and o ening into said diametrical slots; anosciflatory arm centrally pivoted to the boring shaft in saidlongitudinal slot; a pattern bar slidably mounted in one of saiddiametrical slots and pivotally connected to the oscillating arm at oneend thereof; a cutter bar slidably mounted in the other of saiddiametrical slots and pivotally connected to the oscillatory arm at theopposite end thereof; a cutting tool mounted in the cutter bar; andmeans for giving a reciprocating movement to the pattern bar.

2. In a boring machine, the combination of a rotatable boring shaft,having two diametrical slots; a pattern bar slidably mounted in one ofsaid slots; a cutter bar, slidably mounted in the other of said slots; acutting tool on said cutter bar means for giving a reciprocatingmovement to the pattern bar; and a lever centrally pivoted on saidboring shaft and operated by the pattern bar to give a reciprocatingmovement to the cutter bar.

3. In a boring machine, the combination of a lathe having a head stockand a tail stock; a rotatable boring shaft axially mounted in said headstock and tail stock; a pattern bar carried by said shaft and capable ofa reciprocating movement thereon transversely of the shaft; a cutter barcarried by the shaft and capable of a reciprocating movement thereontransversely of the shaft, which cutter bar is provided with a cuttingedge; means for communicating said motion from the pattern bar to thecutter bar equally and to the same extent; and a pattern having a boremade in different arcs transversely thereof, but continuous of eachother scriatim, with the surface of which bore the pattern bar isconsecutively in contact, said shaft having its axial line parallel withand eccentric to the axial line of said bore.

4. In a boring machine, the combination of a boring shaft made in twolongitudinal half-sections, each semi-circular in cross section and eachabutting the other on the plane sides thereof, respectively, saidsections being made each with two slots and an intermediatecommunicating recess and said slots and recess of one sectionregistering with those of the other section; screws connecting said twosections and having their heads contained in sockets, respectively, soas to be below the peripheral surface of said shaft; a pattern barmounted slidably in one of said registering slots; a cutter bar mountedslidably in the other of said registering slots; and an oscillating armor lever in said intermediate registering recess pivotally mountedtherein and pivotally connected to the pattern bar and cutter bar at itsrespective ends.

5. In a boring machine, the combination of a shaft having a diametricalslot; a lever pivotally mounted on the shaft; a cutter bar mountedslidably in said slot and pivotally mounted on the end of the lever; anda cutting tool on the cutter bar.

6. In a boring machine the combination of a pattern having a patternbore; a pattern bar; and an oscillating shoe loosely mounted 011 eachend of the pattern bar and idapted to contact slidingly with the patternore.

7. I11 a boring machine, the combination of a pattern having a patternbore; a pat tern bar thicker than the depth of said pattern bore; anoscillating shoe mounted loosely in each end of the pattern bar andadapted to contact slidingly with the pattern bore and whose length isequal to the depth of the pattern bore; and two ears at the oppositesides Of each end of the pattern bar adapted to move slidingly along therim of the pattern and to project radially beyond the adjacent shoe andto hold said shoe against longitudinal displacement.

8. In a boring machine, the combination of a pattern having a patternbore; a pat tern bar having a slot in each end; a tapped block mountedmovably in said slot and having a concave seat at its outer end; a shoemounted loosely in said seat and in sliding contact with the patternbore; a screw passing through the tap of said block and having a head atits inner end in contact with the closed end of said slot; and twooppositely arranged ears at each end of the pattern bar in abutment withthe ends of said shoe and projecting beyond the same.

9. In a boring machine, the combination of a pattern having a patternbore; a pattern bar having a slot at each end; a tapped block mountedmovably in said slot of the pattern bar and having a concave seat on itsouter end together with a central recess; a shoe having a convex surfaceand loosely mounted in-said concave seat and in sliding contact on itsouter surface with the pattern bore; a stud extending from the convexside of said shoe into said recess of the block; a screw passing throughthe tap of said block and having its head in contact with the closed endof the slot of the pattern bar; and two oppositely arranged cars at eachend of the pattern bar in abutment with the ends of said shoe andprojecting beyond the same.

10. In a boring machine, the combination of a boring shaft having adiametrical slot; a bar mounted slidably in said slot; a bearing blockinserted centrally through said bar and having a central aperture; twowashers centrally bored and mounted respectively on the outer surfacesof said bearing block; a lever, whose outer end passes through saidaperture of the bearing block; a pivot connecting said lever and bar inthe said bearing block; and a pivot passing through said washers andlever to constitute the fulcrum of the lever.

11. In a boring machine the combination of a boring shaft having adiametrical slot; a bar mounted slidably in said slot and havingarectangular opening; a bearing block inserted slidingly in saidrectangular opening but narrower than said opening, which block has acentral aperture, a lever, whose outer end passes through the apertureof the bearing block; and a pivot connecting the lever and bar in saidbearing block.

12. In a boring machine, the combination of a boring shaft in twolongitudinal halfsections, having two diametrical slots and anintermediate longitudinal recess 0 ening at its ends into said slots,respective y; a pattern bar slidably mounted in one of the slots; acutter bar slidably mounted in the other of said slots; a leverconnected pivotally at its ends, respectively, with the pattern bar andthe cutter bar and extending and movable in said longitudinal recess;and a pivot extending through a central aperture of said lever andthrough registering apertures of said two half sections of the boringshaft.

13. In a boring machine, the combination of a boring shaft in twolongitudinal half sections, having two diametrical slots,' and anintermediate central recess which opens into said slots, respectively,and a central diametrical bore; two bearing blocks each having a centralaperture and avconical seat; a pattern bar slidably mounted in one ofthe slots; a cutter bar slidably mounted in the other of said slots; alever connected pivotally at its ends, respectively, with the pat ternbar and cutter bar and extending and movable in said longitudinalrecess; a centrally perforated trunnion on each side of the leverrotatable in said conical enlargement of the central diametrical bore;and a pivot passing through the said bore, through said trunnions andthrough a central aperture of said lever.

14. In a boring machine, the combination of a boring shaft made in twolongitudinal half-sections and having two diametrical slots; a )atternbar mounted slidably in one of said lots; a cutter bar mounted slidablyin the other of said slots; a transverse bore in the boring shaft; twobearing blocks inserted in said bore and each having a centralperforation and a conical seat; alever connected at its ends with thepattern bar and cutter bar, respectively, and having at its center oneach opposite side a hub and a trunniongf extending from said hub, whichlever, hubs and trunnions have one continuous circular aperturetherethrough, said lever, hubs and trunnions being mounted in arecess'in said half-sections of the boring shaft, which opens into saiddiametrical slots, respectively, and is of a shape adapted to allow anoscillation of the lever; and a pivot passing through a centraldiametrical bore of said half-sections of the boring shaft and throughthe circular aperture of said lever, hubs, trunnions and bearing blocks.

15. In a boring machine, the combination of a split boring shaft, havinga diametrical bore and a longitudinal recess; a centrally perforatedlever mounted in said'recess and having on each side a centrally boredtrunnion shaped like a cone 'frustum; a tubular pivot having two oilpassages and extending through the diametrical slot of the boring shaftand through said apertures of the lever and trunnions a bearing havingaseat shaped like a cone frustum surrounding each trunnion on itstapering sides; a head on one end of the tubular pivot constituting aclosed end thereof; exterior and interior screw-threads at the open endof the tubular pivot; a pattern bar mounted crosswise of boring shaft; acutter bar mounted crosswise of the shaft; a pivotal connection betweensaid lever and pattern bar and cutter bar, respectively; a washerengaging said exterior screw-threads; a screw plug engaging saidinterior screw threads; and an oil duct through said screw plug, allarranged so that oil introduced into the duct of the screw plug flowsinto the tubular pivot and through the oil openings of said pivotbetween said trunnions and the cup bearings thereof.

16. In a boring machine, the combination of a boring shaft having aslot; a cutter bar mounted slidably in said slot; a lever pivot allymounted on the boring shaft; a pivot connecting said lever and bar; anda shield covering said cutter bar at said pivotal connection thereof.

17. In a boring machine, the combination of a boring shaft having aslot; a bar mounted slidably in said slot; a bearing block having acentral aperture and mounted in a slot of said bars, a lever pivotallymounted on the shaft and pivotally connected with said bearing block;and a shield having a central aperture and a plurality of ears, thelatter being inserted between said bearing block and bar and extendingover the bearing block.

18. In a boring machine, the combination of a rotatable boring shafthaving two diametrical slots; a central recess intermediate said slotslengthwise of said shaft; a pattern bar mounted slidably in one of saiddiametrical slots; a cutter bar mounted slidably inthe other diametricalslot; a lever pivotally mounted in the boring shaft in said centralrecess; a pivotal connection of said lever with the pattern bar and thecutter bar, respectively; means for supporting said boring shaftaxially; a pattern having a pattern bore and provided with flanges; acollar on the boring shaft near one end thereof; a saddle integral withsaid collar and having flanges; a stationary pattern holder havingflanges; bolts fastening'the saddle flanges, pattern flanges and patternholder flanges together; a movable collar at the end of the boring shaftin contact with the saddle collar; a set screw holding the movablecollar in an adjusted position; and means for rotating the boring shaft,said pattern bar being arranged within the pattern bore and adapted torotate with said shaft with its ends in constant contact with thepattern bore.

19. In a boring machine, the combination of a rotatable boring shaft; apattern bar carried by the shaft rotatable therewith but slidablethereon; a pattern having a pattern bore with which the pattern bar atits ends is in constant contact; a pattern holder sur rounding thepattern and having a circular opening with a tapering bore; a bushingmade in two half-sections having a straight bore in which said shaft isrotatably supported and also having a tapering exterior surface to fitslidably into the tapering bore of the circular opening of the patternholder; and means for holding said divided bushing in position.

20. In a boring machine, the combination of a lathe havingalongitudinally slotted bed; a pattern; a pattern holder having astandard or tail piece provided with a vertical slot and extendingthrough the slot of the lathe bed; a

cross bar extending across the lathe bed from side to side and having acentral threaded aperture; two dogs slidable upon the cross bar intocontact with the sides of said lathe slot and surrounding the cross bar;a set FRANK J. WATERS. Witnesses:

HOWARD A. LAMPREY, WARREN R. PIERCE.

